1. Technical Field
The present disclosure relates to a separator for a nonaqueous electrolyte secondary battery and a nonaqueous electrolyte secondary battery.
2. Description of the Related Art
As a separator for a nonaqueous electrolyte secondary battery, a porous film made of cellulose fibers is known (for example, see Japanese Unexamined Patent Application Publication No. 2013-99940, hereinafter referred to as Patent Literature 1). As a separator including cellulose fibers for a nonaqueous electrolyte secondary battery, a porous film made of a fibrous material, such as cellulose fibers, and inorganic particles, such as alumina, is known (for example, see Japanese Unexamined Patent Application Publication No. 2008-4438, hereinafter referred to as Patent Literature 2).
However, the separator for a nonaqueous electrolyte secondary battery disclosed in Patent Literature 1 may not have satisfactory air permeability. In the separator for a nonaqueous electrolyte secondary battery disclosed in Patent Literature 2, the retention of the nonaqueous electrolyte (electrolytic solution) is low, and the cycling characteristics of the nonaqueous electrolyte secondary battery may not be satisfactory.